I entered the unit into that mode and took a video of it. I posted it to youtube, so you could see it.

You can see the full diagnostic mode, then me trying to select a cycle to no avail.

In my troubleshooting, I've done a few things:

Cycles the power to the dishwasher from the breaker.

held cancel to run a 2 minute drain cycle.

During the RAKS, I interrupted it once when it was filling, so I know the valve opens allowing water in.

I filled the tub up with several cups of water and held cancel to run the drain cycle. It does completely drain the tub.

I took the control board out and tested all the resistors with a multimeter, all measured resistance match up with color coded resistance level. All the capacitors seems to be free and clear of any corrosion or deterioration. All leads seem fine and the board is generally in good shape. Also, the ribbon cable doesn't appear to have any cuts or interruptions in it.